Variable laminoplasty implant

ABSTRACT

A vertebral implant comprising a first base configured for securing to a first cut portion of a vertebra, and second base configured for securing to a second cut portion of the vertebra. A connecting member is configured to associate the first and second bases at a preselected spacing from each other, and the implant is preferable adjustable to select the spacing.

FIELD OF THE INVENTION

The present invention relates to an implant for bone surgery, and morespecifically to a vertebral implant with an adjustable configuration.

BACKGROUND OF THE INVENTION

In certain pathologies, the spinal canal extending through a patient'svertebrae is or becomes too narrow and constricts the spinal cordextending therethrough. The narrowing may be congenital, potentiallyaffecting patients at any age. Narrowing can also be attributable toother causes, such as age, injury or removal of a spinal disk.

A condition associated with aging, for instance, is spondylolsis, inwhich intervertebral disc loose water and become less dense. Thesedegenerative changes near the disk can cause an overgrowth of the bone,producing bony spurs called, “osteophytes” that can compress the spinalcord. The constriction of the spinal cord in the cervical spine, forexample, often produces pain, weakness, or loss of feeling inextremities. Other causes for narrowing of the spinal canal include discshrinkage, which causes the disc space to narrow and the annulus tobulge and mushroom out, resulting in pressure on the spinal cord.Degenerative arthritis of facet joints can cause joints to enlarge, orthe vertebra to slip with respect to each other, also compressing thespinal cord. Instability between vertebra, such as caused by stretchedand thickened ligaments' can also produce pressure on the spinal cordand nerve roots.

Myelopathy, or malfunction of the spinal cord, occurs due to itscompression. The rubbing of the spine against the cord can alsocontribute to this condition, and the spinal cord compression canultimately compromise the blood vessels feeding the spinal core, furtheraggravating they myelopathy.

Traditional procedures for decompressing the spinal cord include alaminectomy, in which the lamina and spinal processes are removed toexpose the dura covering the spinal cord. Another known procedure is alaminoplasty, in which the lamina is lifted off the dura, but notcompletely removed. Typically, one side of the lamina is cut, while apartial cut is made on the other side to hinge the lamina away from thespinal cord to increase the size of the spinal canal. A laminoplastyplate is then screwed to a facet and to the hinged open lamina. Theplate of an appropriate size is selected and bent to the desired shapeand preferably has a plurality of screw holes. A strut of bone can beplaced in the open portion within the lamina and the facet to help holdthe open position of the lamina. Prior to the operation, the surgeonneeds to measure the vertebra to determine the size of the platenecessary for implantation. At that point, a plate can be selected withthe appropriate dimensions, and implanted at the site.

A laminoplasty implant is needed that preferably allows its size to bevaried prior to implantation, preferably without changing its overallshape or configuration, so that a plate does not have to be customselected and intensively shaped and formed prior to each surgery.

SUMMARY OF THE INVENTION

The present invention relates to a bone implant, and more preferably avertebral implant. The implant has first and second bases configured forsecuring two first and second cut portions, respectively, of a vertebra.A connecting member is configured for associating the first and secondbases at a pre-selected spacing from each other. Most preferably, theimplant is adjustable to select and set the spacing. In the preferredembodiment, the implant is a laminoplasty implant, and the first andsecond vertebral portions are a lateral mass, its articular mass, or itsfacet, or a portion of the lamina, and the second vertebral portion cancomprise, for example, at least part of the lamina.

The first base is preferably in fixed association with the connectingmember. One of the connecting members and second base comprises anadjustable member that is adjustable to select the spacing between thebases. The other of these portions of the implant can include a linkingmember that is associable with the adjustable member. The adjustablemember preferably adjusts the length of the connecting member measuredfrom the first base to a connection location at which the linking memberis associated with the adjustable member. This length is preferablyadjusted without changing the overall shape or configuration of theimplant and preferably by changing the length of the connecting memberwithout modifying the general shape of the bases or the size of theposition of he bases in contact with the bone when implanted.

Also, the adjustable member can define a plurality of mating portions,with the linking member being associable selectively with at least oneof the mating portions to select the connection location. The matingportions and linking member are preferably configured for pivotallyassociating the adjustable member and second base. The mating portionsand linking member of the preferred embodiment are configured to beplaced into the association at a first pivotal orientation with respectto each other, and for connecting the first and second bases secured tothe cup portions in a second pivotal orientation between the linkingmember and mating portions or connecting member.

In one embodiment, the mating portions and/or linking member comprise atleast one or more protrusions receivable in one or more notches of theother of these elements to associate the adjustable and linking membersa protrusion can be selectively receivable in at least one of thenotches for selecting the connection location. At least one of thenotches and protrusions is preferably arcuate about axial directionmeasured with respect to the spinal column, such that the protrusion isreceived for sliding in the notch and in this manner pivoting of theconnecting member with respect to the linking member without sliding inthe notch can be restricted if desired. A loading opening can beprovided, for example, between a pair of the protrusions to receive thenotches of the adjustable member therein for associating the adjustablemember and the linking member. The adjustable portion is preferablyconfigured for severing a potion of the connecting member disposedbeyond the selected connection location from the first base.

At least one of the bases can include a concave contacting surface thatis configured for receiving the cut portions of the vertebra. At leastone of the bases preferably includes a fastener mount portion configuredto attach a bone fastener thereto to secure the base to the vertebra.The fastener mount portion can include a plurality of fastener mountportions that are disposed at different axial locations with respect tothe spinal access. This allows attaching bone fasteners depending on theaxial spacing between the first and second cut portions. A fastener canbe mounted in the fastener mount portions, and in one embodiment thefastener is articularble and includes a universally pivotal head. Thehead is associable with a vertebra joining member, such as a rod and atleast one other vertebra in the spinal column. A further fastener mountpotion can be provided, such as in the connecting member, for securing abone graft thereto. Once the first and second bases are secured to thefirst and second cut portions of the vertebra, the connecting memberpreferably fixes the association between the bases, thus fixing thedistance therebetween and holding the lamina in a desired hingedposition. In a preferred embodiment of an articularble fastener, thefastener has a bone fastener portion configured for fastening to a bone,a head configured for associating with the vertebra joining member, anda universal joint that pivotally associates the fastener portion withthe head for relative universal pivoting therebetween. In oneembodiment, a passage is cooperatively defined by the head and joint topermit access to the fastener portion to engage it directly with thedriver. Thus, a driver can be used to screw the fastener portion intothe bone prior to attaching to a rod, or other vertebrae joining member.

Consequently, an improved implant is provided that can be used in alaminoplasty procedure without requiring the intensive customization ofa bone plate or the selection from a wide size variety of bone platesprior to implantation. Preferably the implants can be customized in situto best fit the patients anatomy substantially reducing the amount oftime and costs to perform the operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are perspective views of a laminoplasty implantconstructed according to a preferred embodiment of the invention,adjusted to different lengths;

FIGS. 3 and 4 are perspective views of alternative embodiments ofimplants with different fastener mount portions;

FIGS. 5 and 6 are a bottom view and a perspective rear view of anotherembodiment of an implant;

FIGS. 7 and 8 are a perspective and axial view of an implant fixed withother vertebrae;

FIGS. 9 and 10 are cross-sectional views of other embodiments ofinventive universally pivotable screws; and

FIG. 11 is a perspective view of another embodiment of an articulatedfastener.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, in a preferred laminoplasty procedure, an osteotomyis performed in which a complete cut is made through vertebra 16,approximately between the lamina 20 and lateral mass 14, such as thearticular mass or facet portion therof. A partial-depth cut 11 is madeon the opposite lateral side, also approximately between the lamina 20and other lateral mass 14. The lamina 20 is then hinged open about thepartial cut 11 to increase the cross-sectional size of the spinal canalto decompress the spinal cord therein.

A preferred embodiment of a laminoplasty implant 10 includes a lateralbase 12 that is configured for securing to a lateral mass 14 of avertebra 16. A lamina base 18 is configured for securing to a portion ofa lamina 20 that has been cut and hinged away from the lateral mass 14.For alternative surgical procedures, the base can be configured forsecuring to different parts of the vertebra, a differently preparedvertebra, or to different bones, as desired.

Preferably, one or both bases 12,18 have concave contacting surfaces22,24 that are configured for receiving the cut portions of the vertebra16, such as at the lateral mass 14 and lamina 20. The lateral base 12 ofthe embodiment shown has an outside portion 26 that is preferably placedagainst the posterior surface of the lateral mass 14 outside the spinalcanal 30, and against an inside portion 28 that is preferably placedagainst a wall of the vertebrae at an angle to the position facetsurface at the cut 32 location, preferably in the interior of the spinalcanal 30. Together, the outside and inside portions 26,28 of the lateralbase 12 define the concave surface 22 for receiving and capturing thecut portion of the lateral facet 14. The individual surfaces of theoutside and inside portions 26,28 can also be concave, preferably by aslight amount.

In the embodiment shown, the angle between the outside and insidepotions 26,28 at the concave surface is about a right angle, but can bevaried depending on the location of the implantation and the angle ofthe cut that is made. Preferably, the angle is between about 30° and150°, and more preferably between about 60° and 100°. In one embodiment,the angle can be up to about 180°, such as by employing an intermediateportion to connect the outside and inside portions. The inside portion28 can be constructed as a lip to capture the edge of the lateral mass14 at the cut, to assist in the proper placement of the implant 10 andprevent or restrict movement thereof after implantaion.

The lamina base 18 also preferably has an outside portion 34, which ispreferably placed against the posterior surface of the lamina 20 outsidethe spinal canal 30. An intermediate portion 36 is configured anddisposed for placement against a narrow edge of the lamina 20, and aninside portion 38 is placed against an anterior surface of the lamina 20inside the spinal canal 30. Together, the outside, intermediate, andinside portions 34,36,38 of the lamina base 18 define the concavesurface 24 for receiving and capturing the cut portion of the lamina 20,preferably surrounding the cut portion of the lamina 20. The insideportion 38 can be configured as a lip to help prevent pivoting of thelamina 20 tending to close the spinal canal 30 prior to the bonehealing.

The angle between the outside and intermediate portions 34,36 in thepreferred embodiment and between the intermediate and inside potions36,38 at the concave surface are about right angles, but can be varieddepending on the location of the implantation and the angle of the cutthat is made. In one embodiment, only two angled portions are used, suchas by providing a lip to capture the edge of the cut lamina, as is shownfor the lateral base 12. The angle between the outside and insideportions is preferably about 180°, but can alternatively be as low asabout 30°, more preferably as low as about 60°, and most preferably aslow as about 90°. The concave surface 24 captures the edge of the lamina20 at the cut, to assist in the proper placement of the implant 10.

The bases 14,18 preferably include fastener mount portions 40 configuredfor attaching a bone fastener thereto. If bone screws 42 are to be used,then the fastener mount portions can define suitable openings forreceiving and fastening the bone screws 42. The fastener mount portions40 are preferably disposed for accessing and inserting the fasteners 42from the outside of the bone, to facilitate implantation.

The lateral base 12 shown has two fastener mount portions 40 alignedlaterally with respect to each other. The lamina base 18 shown, on theother hand, has two fastener mount portions 40 disposed axially withrespect to each other. The position of the fastener mount portions 40can be varied according to the bone available at the implantation site.For instance, the implant 44 of FIG. 3 has facet and lamina bases 46,48,each with a fastener mount portion 50,52 configured to attach a singlebone screw 42. The implant 54 of FIG. 4, however, has a lamina base 56with fastener mount portions 58 configured for receiving and attachingup to three bone screws 42. Alternative bases can secure to othernumbers of fasteners in other arrangements. Similar fastener mountportion arrangements can be used for the lateral base.

The fastener mount portions of implant 54, shown in FIG. 4, has threefastener mount portions 58 oriented generally along the apices of atriangle. Two of the fastener mount portions 58 are disposed generallyat a same lateral location, and at least two of the three are preferablydisposed at different axial locations along the spinal axis whenimplanted. Since the vertebral laminae are displaced downwardly in anaxial direction with respect to the facets of the same vertebrae,axially displaced fastener mount portions, such as in lamina base 56 inFIG. 4 and lamina base 18 in FIG. 1, can help ensure that at least oneor more of the fastener mount portion 40,58 is disposed over bone intowhich a fastener can be placed.

As shown in FIG. 4, the upper fastener mount portion 58 is empty, as itis not completely over lamina bone. On the other hand, the other twofastener mount portions 58 are fully disposed over bone, and each has abone screw 42 secured therethrough. The leftmost fastener mount portion58, disposed closest to the lateral base 12, is preferably disposedaxially between the other two fastener mount portions 58 in a positionlikely to always be able to engage the bone with a fastener. If theimplant 54 were used on the right side of a vertebra, instead of on theleft side as shown, the other of the two fastener mount portions 58 thatare is a close axial position would be over bone and used for securing afastener, while the fastener mount portion that is shown with a bonescrew 42 in FIG. 4 would be empty. In an alternative embodiment, thetriangle may be reversed, with a pair of fastener mount portionsprovided towards the lateral base, and a single fastener mount portionprovided further therefrom than the other two. An alternative embodimenthas an asymmetrical arrangement of fastener mount portions, and oneembodiment has two positioned along a line that is diagonal to thelateral direction between the facet and lamina bases.

Referring again to FIG. 1, implant 10 has a connecting member 60 thatassociated the facet and lamina bases 12,18 at a preselected spacing 62from each other. The spacing 62 is selected to determine the hingedposition in which the cut lamina will be maintained when the surgery iscomplete. The connecting member 60 preferably acts as a strut holdingthe bases 12,18 apart.

The preferred connecting member 60 and/or its association with at leastone of the bases 12,18 is adjustable for selecting the desired spacing62. In the preferred embodiment, one of the bases 12,18, preferably thelateral base 12, is in fixed association, and preferably integral withor of unitary construction with the connecting member 60. The otherbase, preferably the lamina base 18, has a linking member 64 that isassociable with the connecting member 60. The preferred linking member64 has at least one protrusion, such as parallel D-rings, that isassociable with any of a plurality of notches 66 defined between ledges68 on the connecting member 60 to select a location for the connectionbetween a notch 66 and the D-ring.

Prior completing the implantation, such as after the lamina base 18 issecured to the cut lamina 20 but before the lateral base 12 is securedto the lateral mass 14, at least one of the ledges 68 of the connectingmember 60 is inserted into a loading opening, such as a slot 70 definedin the linking member 64 and extending into the facing D-rings, whichslot 70 preferably has a larger cross-section than the cross-section ofthe ledges 68 along a plane parallel to the notches 66.

Once a ledge 68 is placed within the slot 70, the mated connectingmember 60 and linking member 64 are pivotally associated, and theconnecting member 60 can be pivoted about an axis that is preferablygenerally parallel to the spinal axis to place the lateral base 12against the vertebra lateral mass 14, where it can be secured. When bothbases 12,18 are engaged with each other and secured to the respectivebone portions, the connecting member 60 preferably maintains the bases12,18 in fixed association with each other, preferably substantiallypreventing movement between the bases 12,18.

The connecting member 60 is adjustable in length, and preferablycomprises an adjustable member 72, which includes the notched 66 andledges 68. The adjustable member 72 is adjustable to adjust a length ofthe connecting member 60 and thus the spacing 62. By selecting the notch66 to be mated with the linking member 64 D-rings, the length of theconnecting member 60 can be incrementally adjusted. Once the anatomy ofthe vertebra is measured and preferably verified by mating theconnecting member 60 with the lamina base 14 and pivoting the connectingmember 60 and lateral base 12 portion to contact the lateral mass 14,the connecting member 60 can be separated from the lamina base 18. Theadjustable member 72 of the connecting member 60 can then be clipped onthe opposite side of the desired notch 66 from the lateral base 12 toshorten the connecting member 60 and eliminate unneeded material. FIG. 2shows an implantation of the implant 10 with the connecting memberadjusted and clipped to a shorter length than in FIG. 1, thus fixing thelamina 20 at a smaller open hinged angle than in FIG. 1. The shorterarrangement of FIG. 2 can also be used for smaller vertebrae.

Referring to FIGS. 5 and 6, another implant 74 embodiment is shown witha fastener mount portion 76, which is preferably associated withconnecting member 78 and faces the spinal canal 30. Fastener mountportion 76 is preferably positioned and configured for securing a bonegraft fragment 80 to help support the hinged lamina 20 in the openposition, and ultimately for fusing with the vertebral bone when thevertebra heals. A fastener, such as a bone screw 84 is fastened throughthe fastener mount portion 76 to the one fragment 80.

In the embodiment shown, the connecting member 78 is substantiallystraight. Alternatively, the connecting member can be curved, preferablybowed outwardly from the spinal canal to increase its expandedcross-sectional size.

The bone fragment 80 is shaped to preferably contact both sides of thecut 32 in the vertebra 16. The bone fragment 80 is preferably alsoprovided with a notch 86 to receive the inside portion 28 of lateralbase 82 to extend around the cut portion of the lateral mass 14.Although a similar notch can be provided for the lamina base 88, thelamina base 88 of this embodiment does not have a third portion thatextends inside the spinal canal 30. As shown in FIG. 5, the ledges arearcuately curved about an axial direction with respect to the spinalcolumn, preferably following the curved shape of the D-rings of linkingmember 64 and further controlling the relative orientation between theconnecting member 78 and the linking portion 64.

As shown in FIG. 7, an implant embodiment 90 has a lateral base 46 thatis secured to lateral mass 14 by an articulated bone fastener 92, whichis itself secured to at least one adjacent vertebra 16. Fastener 92comprises a fastener portion 94, which is preferably a bone screwportion fastened to the vertebra 16, and a head 96 that is configuredfor associating with a vertebra joining member, such as a rod 98. Alocking mechanism, such as a set screw 102, preferably locks the rod 98to the head 96. A joint 100, which is preferably substantiallyuniversally pivotable and also preferably rotatably, pivotallyassociates the head 96 with the fastener portion 94.

As shown in FIG. 8, an embodiment of the joint 100 includes a link 104configured with two spherical portions 106,108, preferably of differentsizes. Each spherical portion 106,108 is received in a socket 110 of thehead 96 or the fastener portion 94. The sockets 110 preferably extendmore than half way around the spherical portions 106,108 to retain thespherical portions 106,108 therein. A double ball and socket joint isthus provided, preferably allowing rotation, and most preferablyunlimited rotation, at least about the axis of the head 96 or fastenerportion 94. Pivoting is preferably allowed through an arc of betweenabout 10° and 80°, and more preferably between about 20° and 70°,preferably in any direction about the spherical portions 106,108.

A passage 120 is preferably defined cooperatively by aligned openings inthe head 96 and joint 100 configured to receive a driver, such as ascrew driver, to engage directly with the fastener portion 49 to secureit to the bone. The passage 120, preferably is aligned with a driverreceptacle 122 in the fastener portion 94.

The articulated fasteners 92 thus allow other vertebrae to support eachother and can be useful where vertebrae are to be fused. As shown inFIG. 7, a similar arrangement of articulated fasteners 92 and rods 98can also be employed on the opposite facets 14 to improve support andpossibly fixation with other vertebrae.

Another embodiment of a pivoted fastener 112 is shown in FIG. 9, inwhich a double ball and socket joint 114 includes a link 116 with twospherical portions 118 associated with head 124 and fastener portion 94.The joint 128 articulated fastener 126 of FIG. 10 includes adouble-socket member 130 that receives spherical portions 132,134, whichare respectively integral or unitary with the head 136 and fastenerportion 138. The articulated fastener 140 of FIG. 11 has a joint 142with a link 144 that has a cylindrical portion 146 associated with aspherical portion 148, which are received in complementary sockets 150,152 in head 156 and fastener portion 158, respectively. Although thespherical portion 148 can rotate about an axis joining the fastenerportion 158 and head 156, the cylindrical portion 146 is restrictedagainst such rotation.

Referring again to FIG. 8, a unitary facet-base/connecting-memberportion has the connecting member 160 offset from the interior edge ofthe lateral base 46, which is disposed closest to the spinal canal 30,by an offset amount 164, measured laterally in this embodiment. Thisoffset 146 is preferably of similar or greater thickness as thethickness of the bone graft 80. In an alternative embodiment, greater orlesser offsets can be provided, including substantially no offset atall. In embodiments without a bone graft, the offset 154 can provideadditional room for the expanding spinal cord. Also, the connectingmember preferably extends at an angle of between about 100° and 140°from the lateral base.

The preferred materials for use in the embodiments of the implants ofthe present invention include titanium, PEEK (polyetheretherketone) andabsorbable materials such as a polylactic or polyglycolic acid material.Other suitable materials may alternatively be used. The preferredspacing 62 provided by the connecting member 60 is between about 5 mmand 30 mm, depending on the location in the spine in which it is desiredto be employed. For example, cervical implants will typically be betweenabout 10 mm and 20 mm, while lumbar implants will typically be betweenabout 20 mm and 30 mm. The bone screw diameters can also vary accordingto the size of the implant and the implant location, and typically varybetween about 3 mm and 6 mm, with a length of about 8 mm to 20 mm.

While illustrative embodiments of the invention are disclosed herein, itwill be appreciated that numerous modifications and other embodimentsmay be devised by those skilled in the art. Therefore, it will beunderstood that the appended claims are intended to cover all suchmodifications and embodiments that come within the spirit and scope ofthe present invention

1. A vertebral implant, comprising: a first base configured for securingto a first cut portion of a vertebra; a second base configured forsecuring to a second cut portion of the vertebra; and a connectingmember configured for associating the first and second bases at apreselected spacing from each other such that the implant is adjustableto select said spacing; and a fastener fastenable in a fastener mountportion formed in at least one of the first and second bases, thefastener including a universally pivotable head that is associable witha vertebrae joining member that is configured for attaching to at leastone other vertebra in the spinal column; wherein the implant is alaminoplasty implant, and the first and second bases are configured toenclose the spinal canal of the vertebra.
 2. The vertebral implant ofclaim 1, wherein the first vertebral portion comprises a lateral mass ora portion of the lamina of the vertebra, and the second vertebralportion comprises at least a portion of the lamina.
 3. The vertebralimplant of claim 1, wherein the first base is in fixed association withthe connecting member.
 4. The vertebral implant of claim 1, wherein atleast one of the connecting member and second base comprises anadjustable member that is adjustable for selecting said spacing, and theother of the connecting member and second base comprises a linkingmember that is associable with the adjustable member.
 5. The vertebralimplant of claim 1, wherein at least one of the bases comprises aconcave contacting surface configured for receiving the cut portions. 6.The vertebral implant of claim 1, wherein the fastener mount portioncomprises a plurality of fastener mount portions disposed at differentaxial locations with respect to the spinal axis for attaching the bonefastener to at least one of the fastener mount portion depending on theaxial spacing between the first and second cut portions.
 7. Thevertebral implant of claim 1, further comprising a fastener mountportion associated with at least one of the bases and connecting memberand disposed facing the spinal canal for fastening to a bone segmentwithin the canal.
 8. The vertebral implant of claim 1, wherein the firstand second bases are secured to the first and second cut portions,respectively, and the connecting member is in fixing association withthe first and second bases to fix the distance therebetween.
 9. Avertebral implant, comprising: a first base configured for securing to afirst cut portion of a vertebra; a second base configured for securingto a second cut portion of the vertebra and having a linking memberformed thereon; and a connecting member extending from the first baseand being matable to the linking member on the second base forassociating the first and second bases at a preselected spacing fromeach other, wherein pivotal movement of the connecting member relativeto the linking member is effective to lock the connecting member to thelinking member; wherein at least one of the connecting member and thesecond base includes an adjustable member that is adjustable to adjust alength of the connecting member from the first base to a connectionlocation at which the linking member is associated with the adjustablemember, and wherein the adjustable member defines a plurality of matingportions, and the linking member is associable selectively with at leastone of the mating portions to select the connection location.
 10. Thevertebral implant of claim 9, wherein the mating portions and linkingmember are configured for being placed into the association at a firstpivotal orientation with respect to each other, and for connecting thefirst and second bases secured to the cut portions in a second pivotalorientation.
 11. The vertebral implant of claim 9, wherein one of themating portions and the linking member comprises at least one notch, andthe other of the mating portions and linking member comprises at leastone protrusion receivable in the at least one notch to associate theadjustable and linking members.
 12. The vertebral implant of claim 11,wherein the mating portions comprise a plurality of notches, and thelinking member comprises a protrusion selectively receivable in at leastone of the notches to select the connection location.
 13. The vertebralimplant of claim 11, wherein at least one of the notches and protrusionare arcuate about an axial direction with respect to the spinal columnof the vertebra such that the protrusion is pivotally received in thenotch.
 14. The vertebral implant of claim 13, wherein the protrusiondefines a loading opening configured and dimensioned for receiving theadjustable member therein for association with the linking member. 15.The vertebral implant of claim 9, wherein the adjustable portion isconfigured for severing a portion of the connecting member disposedbeyond the selected connection location from the first base.
 16. Avertebrae joining system, comprising: a vertebral implant having a firstbase and second base configured to attach to a vertebra, and aconnecting member for connecting the first and second bases; a bonefastener portion configured for fastening one of the first and secondbases to the vertebra; a head configured for associating with avertebrae joining member that is configured for attaching to a pluralityof vertebrae in a spinal column; and a universal joint that pivotallyassociates the fastener portion with the head for relative universalpivoting; wherein the head and joint cooperatively define a passage thatpermits access to the fastener portion for engaging a driver directlywith the fastener portion for securing to a bone; and wherein theimplant is a laminoplasty implant and the first and second bases areconfigured to enclose the spinal canal of the vertebra.